A rotating nozzle which directs a jet in a rotational path about the axis of a nozzle housing and having a rotor within this housing which can rotate the nozzle body about the axis, driven by the liquid which is dispensed therethrough, has been described interalia in my U.S. Pat. No. 5,332,155, the literature described therein and the literature cited in the file of that patent.
Another rotor nozzle is described, for example, in German Patent Document DE 39 02 478. In all of these nozzles the geometry and structure of the assembly determines the rotary speed of the nozzle and frequently it is desirable to reduce the rotational speed of the rotor member within the nozzle housing.